import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: LXW
 * Date: 2022-04-09
 * Time: 20:32
 */

public class UdpEchoServer {
    private DatagramSocket socket = null;
    public UdpEchoServer(int port) throws SocketException {
        this.socket = new DatagramSocket(port);
    }
    public void start() throws IOException {
        System.out.println("启动服务器");
        while (true) {
            DatagramPacket requestPacket = new DatagramPacket(new byte[1024],1024);
            socket.receive(requestPacket);
            String request = new String(requestPacket.getData(),0,requestPacket.getLength());
            String response = process(request);
            DatagramPacket responsePacket = new DatagramPacket(response.getBytes(),response.getBytes().length,
                    requestPacket.getSocketAddress());
            socket.send(responsePacket);
            System.out.println(requestPacket.getSocketAddress()+" request"+request+"response"+response);
        }
    }

    public String process(String request) {
        return request;
    }

    public static void main(String[] args) throws IOException {
        UdpEchoServer server = new UdpEchoServer(9090);
        server.start();
    }
}
